1. Field
The invention relates generally to a pixel structure, and more particularly to a pixel structure having an electrically tunable photonic crystal layer.
2. Description of Related Art
Current photonic crystal displays employ electrically tunable photonic crystal layers with regular lattice structures. Therefore, due to Bragg reflection, when an external light source is incident, a light having a specific wavelength is reflected. The photonic crystal display may be driven by an applied electric or magnetic field which alters a lattice distance in the photonic crystal layer, so that light of different wavelengths are reflected and an adjustable color display is achieved. By applying suitable electric or magnetic fields, the photonic crystal layer can display light of different wavelengths (e.g., infrared light, visible light of various colors, and ultraviolet light). The photonic crystal layer is a favorable medium for display because it can directly display light of different wavelengths, without the need for a mechanism of mixing red, green, and blue light. Moreover, the colors displayed by the photonic crystal layer has high color saturation, and the photonic crystal layer has a high reflectivity.
However, with electric or magnetic field control, the photonic crystal layer can neither display white nor grayscale directly. Therefore, a pertinent issue for manufacturers to resolve is how the photonic crystal layer displays grayscale and various levels of white.